White House press secretary Sean Spicer speaks during “The President and the Press: The First Amendment in the First 100 Days” forum at the Newseum in Washington. (Saul Loeb/AFP via Getty Images)

White House press secretary Sean Spicer has apologized more than once for falsely saying that Adolf Hitler, who killed millions of Jews in gas chambers, didn’t “sink to using chemical weapons.”

He apologized Tuesday evening, telling CNN’s Wolf Blitzer that making a distinction between Syrian President Bashar al-Assad’s alleged use of the nerve agent sarin on his citizens and what Hitler did was a “mistake.”

Spicer apologized again Wednesday morning at the Newseum: “I let the president down. … This was mine to own, mine to apologize for. Mine to ask forgiveness for.” He called his comments “inexcusable and reprehensible.”

But the Anne Frank Center for Mutual Respect, an organization named after the young Holocaust victim, isn’t buying it.

Steven Goldstein, a longtime critic of President Trump and executive director of the center, said a sincere apology should have happened sooner — not hours later after an avalanche of criticism had dominated social media.

“Here’s why the apology holds no consequences. It took Sean Spicer three attempts yesterday to get his apology right. Three separate attempts,” Goldstein said. “That’s the problem with this administration. It takes a public outcry to get the Trump administration, including Spicer, to do the right thing and apologize.”

“It’s pathetic,” he added. “When you tell me that Sean Spicer apologized, I’d say, ‘Why does it take so many iterations for him to get it right?’ ”

Spicer brought up Hitler during a White House briefing Tuesday in an attempt to condemn Assad’s suspected use of chemical weapons.

“We didn’t use chemical weapons in World War II. You know, you had a, you know, someone as despicable as Hitler, who didn’t even sink to using chemical weapons,” Spicer said. “So you have to, if you’re Russia, ask yourself: Is this a country that you, and a regime, that you want to align yourself with. You have previously signed on to international agreements, rightfully acknowledging that the use of chemical weapons should be out of bounds in every country.”

As the comment gained traction on social media, a reporter asked Spicer for clarification, but the press secretary only dug himself into a deeper hole. He said Hitler did not use sarin gas “on his own people the same way Assad was doing.”

White House press secretary Sean Spicer on April 11 said Adolf Hitler didn't use chemical weapons during World War II. Hitler's regime exterminated millions of Jews in gas chambers. (Reuters)

Shortly after the news briefing, Spicer again attempted to clarify his remarks. He said in a brief statement that he was not trying to “lessen the horrendous nature of the Holocaust.” “Any attack on innocent people is reprehensible and inexcusable,” he said.

Hours later, Spicer appeared on “The Situation Room” with Blitzer, where he apologized: “Frankly, I mistakenly made an inappropriate and insensitive reference to the Holocaust, for which there is no comparison.”

During a Wednesday forum at the Newseum, Spicer acknowledged that his gaffe was compounded by the fact that it occurred on the second day of Passover, the most celebrated Jewish holiday in the United States. April also is Genocide Prevention and Awareness Month.

“It really is painful to myself to know that I did something like that. That, obviously, was not my intention. And to know that you screw up, you possibly offended a lot of people,” Spicer said. “I would ask, obviously, for folks’ forgiveness. … That’s, obviously, a very difficult thing personally to deal with because you know that a lot of people who don’t know you wonder why you would do that.”

Spicer also said that he’s disappointed for having caused distraction from the president’s “successful couple of weeks.”

“Not a very good day in my history,” he said.

Goldstein insisted that the apology was not “from the heart” but rather “a bureaucratic response to an outcry.”

The Anne Frank Center is a New York-based nonprofit organization that targets discrimination and anti-Semitism. Goldstein has long been vocal in his criticism of Trump and his administration.

In a separate statement posted to Facebook shortly after the White House briefing, Goldstein called on Trump to fire Spicer and described the press secretary’s remarks as “the most offensive form of fake news imaginable.”

Asked Wednesday to address Goldstein’s condemnation of him, Spicer referred to what he said at the Newseum event, saying he “will let those comments stand.”

Spicer’s comments on Hitler and Assad have angered those who remain concerned by a recent wave of anti-Semitism in the country and the Trump administration’s relatively muted response to it. In January, a White House statement on International Holocaust Remembrance Day didn’t mention Jews or anti-Semitism. White House spokeswoman Hope Hicks said it was intentional because the staff wanted to take “into account all those who suffered.”